Calibrated scanning spreading resistance microscopy profiling of carriers in III–V structures

Abstract

Two-dimensional carrier profiling using scanning spreading resistance microscopy (SSRM) has recently been reported for Si- and InP-based structures. In this article, we report SSRM measurements solely on III–V material-based structures. We have studied GaAs and InP doping staircase structures, prepared using molecular-beam epitaxy. These structures were then used as calibration standards for the profiling of carrier density in state-of-the-art III–V-based optoelectronic devices. We discovered that SSRM data on GaAs can be obtained with either polarity; however, only one polarity (positive or negative sample bias for n- or p-GaAs, respectively) produces SSRM results that show quantitative correlation with dopant concentration as determined by secondary ion mass spectrometry (SIMS). In comparison, SSRM measurements using both bias polarities on n-InP correlates well with SIMS, while p-InP exhibits a similar polarity dependence to p-type GaAs. A physical model based on a Schottky junction is proposed to explain these results. We also report calibrated SSRM measurements on GaAs and InP heterojunction bipolar transistor structures.

Wet Etching Study of La0.67(Sr0.5Ca0.5)0.33MnO3 Films on Silicon Substrates

“…This resistivity value after wet etching is much higher than the previous electrical measurement 4 due to the total resistance being contributed by tip-surface contact resistance, the spreading resistance of the film, back-contact resistance, and various instrument effects. 20 However, we assume that the same measurement conditions were used during SSRM measurements with the same tip, so the effects of etching on the local electrical properties of the CMR films can be visualized with the SSRM technique.…”

Two-dimensional profiling of carriers in a buried heterostructure multi-quantum-well laser: Calibrated scanning spreading resistance microscopy and scanning capacitance microscopy

“…However, variations in the tip-surface contact resistance must also be considered. 10 In SCM, an ultra-high-frequency ͑UHF͒ resonant capacitance sensor forms the basis of the capacitance detection. The resonator connects to the conductive probe tip via a transmission line.…”

Structural, electrical, and optical analysis of ion implanted semi-insulating InP

“…The dc bias applied to the sample was Ϫ1 V. The contact between the diamond coated tip and InP is known to be Schottky-like, nevertheless, it is possible to relate the sample doping to the measured resistances. 17 Compared to the SCM image, a shift in the features R1, R2, and R3 toward the surface can thus be observed. The substrate appears dark due to low resistance.…”